An off-duty FBI agent shot and killed a pit bull that attacked his dog during a walk in Newhall Friday evening, authorities said.

The Los Angeles County Sheriff's Department in Santa Clarita said the agent was walking his German shepherd on a leash near Piazza Di Sarro and Sierra Highway at about 5:35 p.m. when the incident happened.

"Knowing him, assessing his totality, his personality, the way he presents himself - I definitely would think that he had good reason to go to that extreme," friend Alex Akopian said.

Deputies said a woman was walking her unleashed pit bull in the area when her dog attacked the agent's German shepherd.

The woman who owned the pit bull was apparently feeding the animal just outside the gates of Valle de Oro community when the agent and his pet walked out across the street.

Authorities said the agent tried to get his dog free from the fight, but when he couldn't he opened fire, killing the pit bull with a single shot.

Neighbors said the woman does not live in the gated community. It's unclear why she was feeding her dog outside of the gates.

Animal control recovered the pit bulls body and is investigating the shooting along with the FBI since the agent had to discharge his weapon.

Friends describe the agent as a loving family man and said he is devastated by what happened.

"He's very upset and he couldn't even talk to me when I tried to find out what was going on, but he couldn't talk," Akopian said. "He was not good. He didn't look good. He looked as if he was involved in something terrible that happened around him."

Authorities said the German shepherd did not suffer any severe injuries and is recovering at home.